Telephone-exchange.



c. A. ANDERSON a; w. HAGSTROM.

TELEPHONE EXCHANGE.

APPLIOATIDR Hum me.2e.1904.

938,943. Patented Nov. 2, 1909.

C A. ANDERSON & w. HAGSTROM. {TELEPHONE EXCHANGE. APPLQATIQR IZILED AUG 29, 1904.

Patented Nov. 2, 1909.

4 SHEETS-SHEET 2.

G. A. ANDERSDNQ W. HAGS'I'ROM.

TELEPHONE EXCHANGE.

APPLIOATION FILED Aug. 29. 1904.

Patented NW2; 1909.

4 SHEETS-SHEET 8.

c. A. ANDERSON & w. HAGSTROM.

TELEPHONE EXCHANGE.

APPLICATION FILED AUG. 29. 1904.

Patented N v. 2, 1909.

.zuxa V 4 sun's-enm- 4.

NK AIAAAL R vvvvv 1131' it mp UNITED STATES PATENT OFFICE.

CLARENCE A. ANDERSON, OF SALINA, AND WILLIAM HAGSTROM, OF LINDSBORG, KANSAS, ASSIGNORS, BY DIRECT AND MESNE ASSIGNMENTS, 0F TWO-THIRDS TO THE ANDERSON ELECTRIC AND MANUFACTURING COMPANY, OF McPHERSON, KAN- HAS, A CORPORATION OF KANSAS, AND ONE-THIRD TO HAGSTROM BROTHERS MAN- UFACTURING COMPANY, OF LINDSBORG, KANSAS, A CORPORATION OF KANSASv zrmmrnone-nxcnhnen.

Specification of Letters Yatent.

Patented NOV. 2, 1909.

Application filed August 1Z9, 1804. Berta? No. 222,584.

To all whom it may comm; Be it known that we, Gunmen A. AmmaeoN' and VVI'LLIAM ,Hnes'rncm', citizens of the United Stews of America, and residents of Selina, Saline county','Kans'as and of Lindsbot McPherson county, Kansas, r'spethe y, have invented certain new and useful Improvements in Telephone-Exchanges, of which the following is a' specification.

Our invention relates to telephone exchanges and more particularly to party line 1e one exchanges. 'I he object, of our invention ie improvements in the ap aratus used at the s'ub-stittiofls, un'd iht e manner of opereting it from thmain station or een'tialoflice. The ceiling device .nsed it the central 0 es in connection with the present rovements is assumed ioreonvenienee o'fu ind in ordinary use for party line ex- Qehanges. In the accompanying drawings :-Figure 1 is' a" fi'font elevation partly ii'i' section on line 1 91 of Fig. 2, oi? the switching mech- 2,5 aziisnif Fig. -2 .155 a section on, line 2-2 of igi-{JJFi 3 is a. view similar to Fig. 1, hu with t e pertsinioved to simmer positi h1g4 ise' detail cf some of the parts pln Figs. '1 and 3; Fi 5'is a; rear ele- 30, ve ioii' df the lowerpert of V ig. 1" Fig. 6 is :1 .tp ctive of part of 5; B ig. 7 is a Fig. 8 is a diitgren i' e" owing the centriloilice and one local st'ati'on' andFi 9 is a diagram of two other local station" on the same party line with the stations of V i 4 n the said drewm s A is a magnet an ported in a frame .-"-I"he magnet A is polarized by means of a permane t'magnet A ,The armature A is sulpported by a bar A", which her is vertical y udjuetable' on ,gthe posts A by means of the nuts A". 7Nuts A provided with interior insand y 'spiin fserve to noir'h'dllyltdld t entitle .95 time 4 in'itsmidpositiong qx endi ganem' tfi armetgneh ems to turn the ratchet wheel C until a pin (3 on the wheel strikes a sliding pin G which is pivotally supported at C on a brid e A of the frame A. (See Fig. 2&. t the time the pin G strikes the in a. blank pert C of the wheel C reac es the holding awl D, so that further operation of the magnet A is without-effect. The pawl A when retracted slides upon a fixed pin A, and justba'ek of this pin rests the pin C when in its normal osition. On the pawl A is a pin A whic passes over the end of pin 0 when that pin is in its lower position, but which strikes pin C when in l'ts elevated position. In its nor and position the pin A rests slightly to the left of the upper end of the pin C, and

when the ma 'et A is oiierjited to advance the ratchet gel 0 the movement of the pew A is slltflh' that the m A" is always to the left" of the sliding pin C. When a curtent is sent" through the magnet A in a directi'oii 0p osite to the direction used for operiiting', t en' the awl A is moved to carry the pin A" to t e right of the in C if that pin is in its lower posit-ion. f the Pitt (3 Is in itsu per ositionby reason of -1avi been struo an elevatedby the pin C, t en the pin A" will strike the in O and nioyeit to the fight on its pivot In a movement of this iiid, the pin "6 strikes the piif'l)" endlift's the holding pawl D-from the'wfih'e'el C. As a? movement of this kind alsom'dves the driving pawl A away from the rat'ohet' wheel, results in that wheel v86 being released .so that it may be returned to its normal position bg the sptitlgO. viewing this art of t e operation, it willhe seen thatsen ing a; current in one di mien. through the magnet A causes in a" vandi'tfl of the'ratehet wheel Sending a cut Y rent in the opposite dirtlitionithrough the mu dhat will result in oiie'o'f, tirfiithings dep i done. i e ratchetiwheelhajsheen move only i gart of itdcomplet'e forwaid move merit, w en the on1j"thi'ng done will be within a; contact asfljereinafter described; iffl F 1 s ugon whathes bh yprevioiislg ft and returned to its normal position. This release results from the interposition of the pm C between the pins A and D, and this in turn is the result of the final part of the forward movement of the ratchet wheel.

Secured to the spindle C is a contact maker or wiper 4 which swee s over a dial plate E when the ratchet whee C is moved.

n this dial plate are three contact points. One of these ered by the wiper when at its normal position.

, The next contact point E is covered by the wiper when it has been moved one step forward. The third contact point 53 is at a distance from E that de ends upon the particular local station in w ich the switch- Ing mechanism is to be placed. For the first station on the line it is one step of the ratchet wheel 0, for the second station it is two steps and so on. When at its normal position, the wiper 4 engages a spring. 3 an moves it away from a contact spring or point'15. 'When at the extreme of its forward movement, it engages a spring 17 and moves'it away from a contact spring or oint 16. i

, t one side of the frame A is a magnet B whose armature lever-B extends behind the ratchet wheel 0 and which carries a pin B Su ported at a convenient place is a pivoted ever B having a notch B adacent to the pin B against which pin the lever B is drawn by the 5 ring B. When the magnet B is energize the pin B descends and is caught and held by the notch B. When the lever pin 13* is released and rises to. its normal position. This last is due to the fact that the armature end of lever B is of suflicient weight to overbalance the end that carries the pin B.

On the back of the ratchet wheel 0 1s a in C adapted to strike the lever B and re case it from the pin B when said wheel returns to its normal osition. When the wheel moves forward t e pin 0 leaves the lever B so that that lever may catch and hold the pin B whenever the magnet B is actuated.

Directly beneath the armature lever B are three contact sprin s 60, 61 and 67 which are normally separate from each other, but which are closed to electrical contact with each other when the armaturelever B is attracted by the magnet B.

On the armature lever A is a pin or projection 54 which is free from an adjacent spring when said lever is in its normal position and also when it is operating to move the ratchet wheel C, but which electrically engages said spring when a current flows in a reverse direction through magnet A.

Anexchange of the kind herein involved 27 of the diagrams) 1s oov- B is pushed back, the

consists of a central oflice-anda series of local stations connected together by a party line. The party line herein used consists of a single wire and a ground connection. Such party line exchanges have heretofore been made with varyin degrees of success, but all have had their aults.

The construction of the switch just described and the devices and connections for opfrating constitute the improvements by w ich we make such exchanges more successful.

At the central office are a calling device,

a generator, an ordina telephone set, a drop, spring jack and p ug for each party line running from the central ofiice, a battery, and certain ke s, connections and contact ,sprin as wil be readily understood from the rawing and the description of the circuits.

At each local station there are a switch like that described, a telephone set, a receiver book, a generator, a bell rin er, a condenser, a battery, and contacts an connections.

One of the peculiarities of the present invention consists in the relationship existin between the construction and operation 0 the switching mechanisms and the nature of the impulses sent from the battery and genorator at the central office. As there is only one com lete circuit-involving the central' oflice an the various local stations, it will be evident the electrical impulses for calling the central otlice, those for talking between the calling station and the central oflice, those for operating the switching mechanisms, first for selecting the required station and second for connecting the selected station telephonically to the party line, those for signaling the selected station, those for talkin between local stations, those for rin ing 0 and those for returning the switching mechanisms to their normal positions must all travel over this one circuit. a

While it is possible that an exchange mi lithe operated with some of these im- Vu see omitted, the applicants provide means y which they all may be used. As before stated, part of these means consist in the construction and operation of the switching mechanism, and part in the kind and direc-' tion of the electrical im ulses sent.

It will be remembers that impulses sent in one direction through the magnet A cause an advance of the switching mechanisms step by step, while im ulses sent in the opposite direction close ecctrical connections and release the switching mechanisms so that they may return to normal position. The electrical connections made by reverse currents are also used to connect selected stations telephonically to the party line, while release disconnects the connected stations. Hence it is necessary that release ios Ill)

ringer. .A 'pulsating circuits scans should not always occur as a result of a reyerse current, but only under s ecial cirfllmstanoes. This is accom lishe by makmg releasa' impos ible unti the switch has moved to its extreme position.

As electrically operated switches sometimes miss a step, unison is secured by sending more operatln impulses than necessary and stopping the witching mechanisms at definite positions y causing them to strike an abutment. r

In making the icoiine'ctions within the 10- cal stations it happens that if a subscriber who .was not wanted had his receiver removed from its hoo'k part of the operating current w uld pass over a branch circuit and connect that station to the line. To overcome this, a condenser Vis'placcd in this branch which is' part of the ringing circuit. The problem" is to operate the ringer. A battery or an ordinary direct current generator cannot be used because a condenser stops currents from such sources.

An alternating current cannot be .used because a branch of this circuit goes through the operatin ma et A and an alternating current wo d re ease the switching mechanism and .disconnect the station. Under these circumstances we have recourse to a pulsating generator and a polarized bell nerator is a direct enerator whic has its current short during a part of its revolution, with the result that the current flows over the line in pulsations. We" have discovered that a direct current, when sent 'in ulsa- .current I @tions of sui'ficiently hi'gh fre uency wi pass qthrouegha condenser and will opeiate a pomagnet, but will not operate a nonpolarized one. As there is a branch of this circuit through themagnet- A, the direction of the pulsations is that for operating. As the switch, at the time these ulsations are sent, has been stopped by stri in an abutment, they are without effect. I the ring- 'lariz ing had been when the switches were in normal position, then the ulsations would have been in the op osite direction.

The calling evice consists of a dial provided with a series of holes, each one re resenting a difierent station on the party ine.

Pins are insertedin the holes of the 'sta tions wanted and the lever of the calling device is turned to make connection with these pins. Each time a in is touched by a sprin on the lever, e ectrical connection iscomp eted from the metallic'ring. in which the gins are inserted and whic rests in the position shown. and a ratchet wheel is lnmlpib'lfli between the lever and the aothot the contact mob the, spindle Son ing device is rotated onlywhile the lever is being returned to normal osition. The train of ears is so arranged t at the contact making evice 36 will be rotated once during the time when the lever is movi 1 the space between one hole and the next a acent one.

We will explain the operation by assuming that the subscriber at station No. 1 wishes to talk to the subscriber at station No. 3. Either before or after removing his receiver, the subscriber operates his generator G which is of the ordinary direct current type. A current then flows G. 19--18-17-16-14--13ground- 1211--D 1O9- 87-65 -4-32 1-G. This operates the linedrop D and calls the operator. The other line drop D is for another part line shown extending to the left at 75 T e operator then presses key to the right when the talking circuit The key 25 is one of a well known kind which is normally held in its mid-position b the adjacent springs, but will stay at the p aceit is put when pushed toone side. After having received information as to the station calling and the station wanted, she pushes the, key-25 to the left and inserts a plug in the connected spring jack. 7

For reasons hereinafter explained, the first hole in the dial of the calling, device is for a special urpose and the second hole is used for the rst station. The operator therefore inserts pins in the second and fourth holes. She then moves the lever by hand past as many contacts as there are stations on the line and returns it to its "normal ition causing a rotation of contact ma er 36. When 36 connects to 35 a current flows battery X3435-.36-.37--38-39 33 876-A40--14- 13 ground 12 4'142-43-44.45,46- -X. This current flows through each station and moves the switch mechanisms forward. It is re eated so as to bring all switches to a stop wit pins' lie;

will be the case for stations land 3, a cur- 49--46--X. T is'isacurrentin a-reversedh' 'rectionthrought emagnetsA. Asthisoccurs before the .fi itches have reached the end of she may the 91.1.1 res i t close to 55 at each station. one of the stations has itsfimper 4 on the contact 53 and at that station a local current en this occurs,

flows :--battery 2-61-15 52 58 --4 +1- magnet B and places the *2 67 in electrical connection wit each other. As the pins were placed in dial 49 so as to select stations 1 and 3 it is at these stations that this action occurs. As soon as the lever is returned to its normal osition, the conse quence of which is that a 1 switching mechanisms are at their extreme positions, the operator turns her generator crank when a pulsating current flows :-g-57 58-59- 25-76-of the called stations-54 17181960-61 62 -32 \V- 14l3-ground1226-G. The branch from (S through A and 40 to 15 being in the same direction as the operating impulses does not release the switch, and the switch being already stopped by striking its abutment, this branch is without effect. The impulses through the bell ringers Q call the subscribers, after which the talking circuit between stations is :-R at station No. 1- 29K-30-31-H32VV+1413 round to station No. 3-.13-1 4 32 1-31-30K29-R-28-66-67 6O 191817-'45--6.7 back to station No. 165417-1819--6067(i6- When .through talking, the subscriber rings 011' as follows :G-201918 17 45-67 83339687071 72 7311-12 ground 13-14[15-32-- 1G. This operates the clearing out drop 68 and notifies central that conversation is finished. There is a branch of this ciigzuit from 6 to 14 through A but as the current flows in the operating direction itdoes not release the switch. By referring back to the original ringing circuit, it will be seen that there is the same branch but in that case the flow was in the opposite direction and did not operate the switch. At the time of first calling central, the switch was in its normal position, hence to prevent moving it when calling the current is made to flow in the release direction. At the time of operating the clearing out drop, the switch was at its extreme position, hence to prevent releasing it prematurely, the current is made to flow in the operating direction. In other words, the movement of the switch from one extreme to the other reverses the direction of theeurrent from the local generator for the purpose of preventing that current from affecting the position of the switch. At intermediate positions the generator current is shunted as follows :--G-201918.

1716-14.15321G. To release the switches the operator presses key 79 to theleft when wcurrent flows: Xfi34-7 t- 76 41-12- round to all stationsl3l4 40A-fi- 8 33 -39 78 79-46-X. l

The contact point 1'11 being connected to 53 and B, and being atthe same distance from normal on all switches, a pin inserted in the first hole of the dial 19 will connect all stations simultaneously to the party line.

What we claim is:

1. The combination with the conductors, the stations, and the switching mechanisms of a party line exchange, of connecting and releasing devices for each switching mechanism but normally disconnected therefrom, a magnet for hdvancing the switching mechanisms simultaneously step by step, means by which upon the switchin mechanisms being advanced they will ma e temporary connections in succession to their connecting devices, and means by which upon further advance they will make simultaneous operative relationships between their releasing devices and said magnets so that said magnets may directly operate said releasing devices,

2. The combination with a switching mechanism, and a magnet for advancing and for releasing it, of a holding pawl normally not operated by said magnet and its armature, and means by which. the advance movement of said switching mechanism serves to cause said holding pawl to be operated by the armature of said magnet.

3. The combination with a switching mechanism arranged to be advanced by impulses sent therethrough in one direction and to be released by impulses in the oppo site direction, and a source of electricity from which im ulses in either direction may be sent throng said switchin mechanism, of a signaling dev ce, means iv which an impulse in the operating direction may be used to operate said signaling device, and means by which such an impulse used to operate the signaling device 15 inoperative upon the switching mechanism.

4. The combination with a switching mechanism, a magnet havin an armature arranged to be moved in either-bf two dis.

rections according to the direction ofthe impulses flowing through said magnet, and means whereby a movement. of the armature in one direction serves to advance said switchin mechanism, of a holding pawl arrange to be released by a movement of the armature in the opposite direction but normally not in operative relationship to said armature, and means by which the advance movement of said switching mechanism serves to bring about such operative relationshipfbetween said holding pawl and the armature.

5. The combination with a switching mechanism, a magnet having an armature arranged to be moved in either of two directions, and means by which a movement inone direction serves to advance said switching mechanism, of a holding pawl ,a'r ranged to be released by a movement of the armature in the opposite direction but nornially not operated by the armature, a de- HLYIQB arranged to cause said holding pawl rsc to be operated by the armature, and means for opcratin said device by the forward movement 0 the switching mechanism.

6. The combination with u sn'i tchin mechanism, a magnet for advancing it, an means by which said switching mechanism may be released by a reverse operation of said magnet, of a holdin pawl normally not in operative relationship with said magnet so that such reverse operation will not release it, and a device ended by the advance of said mechanism so as to bring about an operative relationship between said pawl and said magnet.

7. In a telephone exchange, the combination with a switching mechanism, a signaling device, electrical connections having branches through both the switehi mechanism and the signaling device, an means by which said switching mechanism is advanced by impulses sent in one direction over said connections and is released by an impulse in the opposite direction; of means by which impulses sent over said connections to operate said signaling device are prevented from either operating or releasing said switching mechanism.

8. The combination with a switching mechanism, a signalin device, and elec trical connections including both, of means by which impulses sent over said connections are caused to operate said switchin mechanism without operatic said sigua ing device, and means by which similar impulses sent over said connections are caused to operate said signaling device without operating said switching mechanism.

9. The combination with a. sivitehin mechanism, a si aling device, and electrica connections inc udi both, of means by which electrical im iii ses sent over said connections and capable of moving both are caused to operate either without operating the other.

10. The combination with an electric circuit, a battery from which impulses may be sent, and a condenser in said circuit for stoppiii impulses sent from said battery. of a. po arizcd magnet located in series with said condenser in said circuit and normally not operable by direct impulses delivered to said circuit, and means for delivering to said circuit at a high frequency iiii iilses similar to those stopped by salt cont enser whereby such impulses are caused to operate said inn 'net.

ll. 'l ie combination with an electric cir cuit, ii polarized magnet in said circuit, and a condenser arranged to normally prevent impulses of a constant. polarity from operating said imignet, of means for deliverin such impulses at a high frequency to suit circuit wla-mby said condenser becomes inoperative to prevent the operation of said magnet.

arranged to he op-- 12. The combination with an electric circuit having two branches, :1 switching mechanism in one branch, and a signaling device in the other branch, of means by which impulses delivered to both branches and adapt ed to operate the signaling device are caused to operate the switchin mechanism only. and means by which otier impulses similarly delivered and adapted to operate the switching mechanism are caused to operate the signaling device only.

13. The combination with a circuit having two branches, :1 switching device in one branch, and a signaling device in the other branch, of a condenser in the branch containing the signaling device for causing impulses of constant polarity to be inoperative on the signaling device, and means for sending such im ulscs at a high frequency so that they wil operate the signaling device located in the branch containing the condenser.

l-l. The combination with the electrical connections of a telephone station, and a switching mechanism adapted to be advanced when impulses sent over said connections pass through said mechanism in one direction and to be released when they pass through in the opposite direction, of a generator adapted to send impulses over said connections and through said mechanism and means b which the impulses from suit generator wi 1 pass through said switch ing mechanism in one direction when it is in its normal position and in the opposite direction when at its extreme forward movement.

15. The combination with the electrical connections of a telephone station, and a. switching mechanism adapted to be moved in opposite directions when impulses sent over said connections pass through the mechanism in opposite directions, of a generator adapted to send impulses over said connections, and means by which such inipiilses will have their direction throii i] said mechanism automatically reveised y the arrival of the mechanism at either extreme of its movement.

11'. 'lhe. combination with electrical connections, and a switching mechanism arranged to have the direction of its moveliieiits determined by the direction of impulses thercllirough. of a enerator, llleillla iy which iin nilses from r-iiiltl generator pathrough said mechanism in opposite direclions when it is at the opposite ltxilclllta' of its movement, and means by which such impulses are shunted when the mechanism is at intermediate positions.

IT. The combination with a switching mechanism, means for advancing it from its normal position, and devices by which it is released so that it may return to its nornial position, of a telephone set, it signaling lot device, and means by which the linal aid-'i with a movable armature, of a holding pawl vancr movement of the switching mechanism r t'tll'tfa to complete connection to the telephone set and to the signaling device and also brings the releasing devnre from inoperative to operative position.

18. The combination with a switching pulses sent over said connections and also I capable of operating both are prevented from operating the switching mechanism while the signaling device is being operated. t

19. The combination with a switching mechanism, and a magnet therefor provided for said mechanism, and a movable body inter wsetl by the movement of said mechanism between the armature and the holding pawl so that a movement of the armature will serve to release the holdin pawl.

20. The combination with a rivin pawl. :1 switching mechanism moved there v. and a holding pawl, of a pin interposed by the movement of said mechanism between the driving pawl and the holding pawl so that a movement. of the former mar be convcvvll to the latter.

Signed at Chicago, Ill., this 17th dav of August 1904.

CLARENCE A. ANDERSON. WILLIAM HAGSTROM.

\l'itnesses:

C. L. REDFlI-ILD, W M. T. ANHELL. 

